PfGCaMP3 transgenic parasite as a tool to study the cytoplasmatic fluctuations of calcium in Plasmodium falciparum

• Grant number: 15/16483-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: September 01, 2015
• End date: October 31, 2017
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Célia Regina da Silva Garcia
• Grantee: Mateus Fila Pecenin
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/51295-5 - Functional genomics in Plasmodium, AP.TEM

Abstract

About 40% of the world population lives in endemic areas of malaria, a disease that mainly affects developing countries such as of Africa and countries under development. The etiological agent of malaria is Plasmodium, an Apicomplexan parasite, and the species P. falciparum is responsible for the most clinically severe picture of the disease. The transmission between vertebrate hosts occurs through Anopheles mosquitoes. The life cycle of Plasmodium alternates between two hosts: (i) mosquitoes, where mating occurs; (Ii) and vertebrates, in which the parasite invades hepatocytes and then erythrocytes, multiplying asexually. Studies from our laboratory show that calcium is the second messenger activated throuht melatonin signaling pathway and this activation culminates in the timing of the parasites during intraerythrocytic phase. In parasites of the Apicomplexa gender calcium plays an important role in the secretion of micronemes during in cell motility, invasion and egress from the host cell and cell differentiation. Several studies have shown evidence of the existence of two distinct compartments of calcium stores in Plasmodium: endoplasmic reticulum and an acid compartment. Our group demonstrated that mitochondria participates in calcium sequestration when the parasite is exposed to high cytoplasmic concentration of this ion. Too much invasive protocols for loading the parasite with calcium markers are used to study the dynamics of calcium in the malaria parasite, P. falciparum, and these protocols do not enable to distinguish between the signal from the host cell and the parasite. Therefore, this project has the objective to study the dynamics of Ca2 + in the P. falciparum malaria parasite using as a tool the transgenic parasite PfGCaMP3, developed by our group, analyzing the role of the endoplasmic reticulum and mitochondria in homeostasis and signaling of Ca2+ during intraerythrocytic stages of the parasite. Furthermore, compounds with similar structure to melatonin will be evaluated using PfGCaMP3 as antimalarial capability, which can contribute to the development of new strategies to combat malaria. (AU)